Hose + Coupling World December 2021 Sample - Page 42

TECHNICAL ARTICLE

Hoses for Hydrogen Fueling Stations

The world is transitioning away from fossil fuel towards renewable sources of energy , and hydrogen is a promising alternative . It is plentiful – the most abundant element in the universe ; and versatile - it can be used both as a fuel and as a storage medium . Hydrogen is not a one-size-fits-all solution , as it has significant drawbacks , but one of the applications where it might develop a useful niche is in transportation . More precisely , it can be used as a fuel for light and heavy vehicles . Japan , Germany , and the United States are some of the countries that already have a network of hydrogen fueling stations , and a key component on them is hoses . They are the final link between the dispenser and the end user and need to withstand very challenging conditions . To understand this transition it is beneficial to learn more about hydrogen as a source of renewable energy and the role hoses play in conveying it for the automotive industry .
By Davi Correia , Senior Mechanical Engineer
Case Study
Hydrogen ( H ) is the first element of the periodic table . If one remembers their chemistry lessons , they know that the chemical elements are arranged in order of increasing atomic number ; and that the atomic number is somewhat related to the size of an atom . As hydrogen is the first element in the periodic table ( atomic number 1 ), it comes as no surprise that it is a very small element as well as the lightest . As a consequence , hydrogen can leak easily .
Hydrogen is the simplest of all elements , and can be pictured as a single electron orbiting a single proton . As this arrangement is highly reactive , hydrogen atoms naturally combine into molecular pairs ( H 2 , known as molecular hydrogen ). At ambient temperature and pressure , H 2 it is a colorless , odorless , tasteless , non-toxic , and highly flammable gas . However , even as a molecule , hydrogen is still highly reactive , forming covalent compounds with most non-metallic elements . As a result , most of the hydrogen on earth is found in more complex forms such as water or organic compounds .
For automotive applications being small and light means that high pressures are required to achieve useful energy densities .
Figure 1 : Total U . S . Greenhouse Gas ( GHG ) emissions by economic sector in 2019 . 3
Hydrogen Production
There is a diverse range of markets for hydrogen applications . Some of the industries using it include : oil refining , ammonia and fertilizers production , metals production , methanol production , food processing , and electronics . Now , if hydrogen is not found freely on earth , where does it come from ?
In order to be consumed in these industrial applications , hydrogen needs to be removed from some other molecule . Today , the two most common feedstocks for hydrogen production are natural gas and water ; and the related extraction processes are natural gas steam reforming and water electrolysis , respectively . “ With respect to the energy required , it is easy to remove hydrogen from compounds that are at a higher energy state , such as fossil fuels . This process releases energy , reducing the amount of process energy required . It takes more energy to extract hydrogen from compounds that are at a lower energy state , such as water , as energy has to be added to the process .” 1 In a nutshell , obtaining hydrogen from natural gas is cheaper , but the process results in Greenhouse
Figure 2 : Diagram of a hydrogen fuel cell . 6
42 Hose + Coupling World , December 2021